FAR INFRARED STUDIES OF HYDROGEN BONDING IN CARBOXYLIC ACIDS
Loading...
Date
1966
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
Propanoic, but a notice and pentanoic acids have been shown by X-ray diffraction to be hydrogen bonded cyclic dimers in the solid state. We will show far infrared spectral evidence that the other straight chain acids through dodecanoic are also cyclic dimers in the solid state, and that all these acids exist as cyclic dimers in the liquid state. This behavior contrasts with that of formic and acetic acids, which form hydrogen-bonded polymers in the solid state, and in the case of formic acid, a polymer in the liquid state. Assignments and mass-frequency relationships of the three infrared-active hydrogen bond vibrations in this series of acids will be discussed, Normal coordinate analyses show that these vibrations approximate a stretching mode, an out-of-plane bending mode, and a twisting mode. Spectral differences with phase changes (liquid-solid and/or polymorphic solids) will be shown and discussed. Rotational isomerism is involved in some of these changes. Some of the C--C torsions have been identified.
Description
Author Institution: Battelle Memorial Institute
This research has been sponsored by the Air Force Office of Scientific research (SRC)-OAR, U.S.A.F., Grant No. AF-AFOSR-911-65.
This research has been sponsored by the Air Force Office of Scientific research (SRC)-OAR, U.S.A.F., Grant No. AF-AFOSR-911-65.